Economical processes for separating solutes from solvents continues to prove difficult even with advanced filtration technologies. For example, extracting purified water from saline continues to be an expensive and inefficient process. High concentrations of salt disposed in saline is known to cause membrane filtration systems to rapidly become inoperable, because high solute concentrations are osmotically and thermodynamically too stable for the more common reverse osmosis, which fail under high pressure required to reverse osmotic pressure.
As noted, reverse osmosis systems rely primarily on polymeric membranes, where fouling from suspended solids continues to be problematic. Salt content of ocean water averages about 3.5%, brackish water averages about 0.3% and fracking well water, if recycled, saturated at about 24%. At low values, reverse osmosis systems require high amounts of energy to operate and require significant amounts of maintenance to address membrane fouling. Salt content in fracking solutions is known to be considerably higher, rendering the use of reverse osmosis systems, for energetic reasons, nearly non-viable.
Attempts to use nano-technology, otherwise molecular sieve, in the fracking industry has provided new opportunities for filtering brines produced during fracking. Current polymer based systems for extracting the salt and other solutes from water have proven inefficient and expensive. The high concentration of salts and other solutes have rendered nano-technology relatively useless due to required frequent cleaning of filter media, which this automated system overcomes.
By contrast, it would be desirable to provide membrane filtration medias that are stable at high pressures, positive on the retentate side and negative on the permeate to enhance throughput for large scale field operation, an enhanced pervaporation. Therefore, a need exists for an apparatus and process capable of removing salt and other solutes at the nano or molecular level from, as examples, concentrated brines, brackish and ocean water and other contaminants including toxins, by efficient and self-maintaining.